Statistical Analysis of "Energy Transfer" Thread f

Basically, on the X axis, you have a measurement of Bullet energy, as a function of muzzle velocity and bullet weight in grains...
This is listed in an increasing array....

On the Y axis, you have the wound area, measured in inches^3.
THIS IS THE VOLUME of the wound. Which translates into "X" which is given, "Times 1", "Times 1"....

ie: If they give you "2" as the wound area, it translates into 2x1x1...

I think that this is how it works...

CGuns

The assumption that wounding potential is equal to the cylindrical volume of the slug passing through the tissue is a bit oversimplfied. Most of the discussion I've seen about wounds talk about the permanent and temporary cavities caused in the tissue. It's the permanent cavities that really count....and it seems logical that the link between energy and channel size would be the strongest there.

Likewise, energy transfer is a bit more complicated than calculating the kinetic energy of the round. Is the transfer (i.e., the collision) elastic or inelastic? What is the transfer mechanism? You mentioned shot placement, Kony, and that's key. Big difference if you hit soft tissue vs. solid organs or bone.

I guess if there was an easy way to analyze bullet effectiveness, someone would have figured it out by now!

Someday I'll put my Master's Degree in physics to use -- maybe make my teenager do a science fair project on it!

Jim

This is really an interesting read:
http://www.thefiringline.com/forums/arc ... 47579.html
I found it after I did my previous post on this thread.

After I read this from an intelligent person, I will still stick with 9mm...I own guns in 10mm and in .45ACP, but, I absolutely can't stand .40SW.

On the thread above from TFL, a MD comments on rounds, etc...A good read.

jdthaddeus11-27-2000, 03:13 PM
The Dr has some good info, but makes the same mistake that many do when talking handgun ballistics: we are not talking about killing, we are talking about STOPPING.
What the patient is like in the OR has no relation to what he did before he got there. That is a flaw that (as a fan of Fackler I can say) that Fackler makes. A lot happens before the BG gets to the OR and the morgue. As a scientist, I do not fully respect Sanow's studies, but I do respect him for trying to find out what happens on the street. The street seems to show that energy dump does induce a person to cease their actions faster ("stop"). A STOP is what matters, not a kill. The 9mm has been proven time and again by many studies to STOP as well as the .45. Sanow wanted to demonstrate the stopping ability of the rounds, and found that the .45 is a very poor energy displacer. The 9mm not only makes a bigger hole, but displaces more energy into the tissue, with potential to be more damage. The .45 was never seen to tumble in the test (PLEASE everyone go read the damn thread or the article and don't just hipshot comment on what you read here).
Personally, with my experience in medicine, I sure don't want to have to wait for someone to bleed out for them to stop coming at me. Does everyone here know how long it takes for a person to bleed into incapacitation?

Hollowpoints do NOT work better because they make bigger holes, they work better because they dump energy faster (eg .357 Magmum). At least, that is what Sanow is saying. Just read the article everyone, rather than going off of a few lines you see here. Most of the article is posted in the thread by yours truly.

As a person in the medical field myselfs, having seen numerous GSW of all calibers, as well as doing a lot of studying, I have NOT seen it true that any caliber stops or kills any better than the other. I have seen guys that took a whole magazine of .45 to all parts of his body and felt it was no more than a nuisance. He never lost consciousness. I have shot animals with both and seen no difference in effectivness or damage. Sometimes 9mm fails miserably. Sometimes .45 fails miserably. Somewhere around here there is the account of the guy that took around 27 rounds of .45 and kept coming. Both rounds fail miserably on occasion. Shot placement is what stops, and shot placement is what kills. A little luck helps too.

I am not a Sanow fan, but no one can argue with the effectiveness of the .357 Magnum. That round is based wholly on energy dump, and it is a reknownwed stopper on the street. The energy dump from a high power handgun round is likened to a kick in the guts, (inside your guts where muscle rigidity cannot defend against it), and that is why people stop more often from energy dump. Without energy dump, many people say that they never even felt getting shot (for instance, a slow arrow dumps very little energy whereas a .45 hitting the chest and stopping instantly just dumped ALL of its energy instantly). I want the BG to FEEL it when he gets hit. Most modern 9mm +P loads have the same energy dump as a factory loaded .357 out of a medium length barrel, and my local LEOs as well as the INS and others claim that the 9mm works great in many many real shootings.

And with all of this, the argument goes round and round.
Just read the article with an open mind, it is quite interesting.
The most maddening thing about this thread is that it appears that the far majority have not even read the article, and few with an open mind.

Here is where I come from with all of this: It is tough to distinctly say these days that the .45 is any better than the 9mm, and in some cases the 9mm is said to be better. We have hundreds and thousands of shootings, many detailed studies and experts and few to none of them can prove that a .45 stops any better than a 9mm. On the street, time and time again, they work the same; they both often fail miserably and both succeed the same. Now, if they are so similar in performance that it can be effectively argued that there is no difference, then I want to gun that carries 16 rounds of ammo over the one that carries 7. That is why I carry a 9mm Glock 19 right now, and maybe a .357 Sig in the future. If they all work about the same, then I want the one with the most chances to make good hits on multiple assailents (more ammo). Shot placement...good HITS...are all that matter, so I like the gun that gives me the easiest hits and the most chances.

What Sanow says on 9mm FMJ vs .45 FMJ is summed up that: 9mm tumbled EVERY TIME, and .45 NEVER tumbled due to bullet shape. Therefore the 9mm actually made a BIGGER hole! The 9mm also goes faster and therefore even when it does NOT tumble, it displaces energy faster into the target. 9mm dumped way more energy AND made a bigger hole. How can you argue with more energy dump and a bigger hole? Most people assume that, upon hollowpoint failure, a .45 is a better bet. Sanow's article shows that that is not necessarily true, and perhaps totally false.

Some of this was covered in my recent CCW class.

Basically, what matters most is bullet weight.

A lightweight bullet travelling at high velocity is generally less effective than a heavier bullet at slower velocity. The heavier bullet will have better penetration due to the inertia it has when striking a target.

There was a whole slew of ballistics test done in the 1980s that were 100% flawed. They took the temporary wound channel into account, and came to the conclusion that a high-velocity bullet did more damage than a low-velocity bullet, even of larger caliber.

However modern ballistics testing - including data collected from actual wound victims as well as tests done on pig cadavers - proves that the temporary wound channel has nothing to do with tissue damage. It is the permanent cavity that causes injury and death.

The .45 caliber round is now a highly recommended cartridge. It is slower, but far heavier. And it is the bullet weight that causes wound damage and effective penetration.

The exact details of everything escape me now; I just can't remember it all.

I do feel safe with 147 grn. 9mm, however. Truth be told, if the round is cheap, it allows me to practice more. And as stated before, a well-placed .22 is better than a missed .45. For me, a 9mm represents a fine round for target, practice, and defense.

But the next time some 1911-toting fella wants to tell you about the "knockdown" power of a .45, or that one shot "can take your arm off", or that people have been spun around by just being grazed by a .45, tell 'em their full of shit. None of that has ever, nor will ever, happen. The .45 is a powerful round and a fine choice for defense. However in order for a bullet to be powerful enough to knock a man down, or blow him off his feet, physics states it would be powerful enough to do the same to the SHOOTER. Doesn't happen, and never will happen.